1. Field of the Invention
The present invention relates to: a tape printing apparatus and a method of controlling printing by the tape printing apparatus in which a print image is printed by using a thermal print head onto a tape which is an object to be printed; a program; and a storage medium.
2. Description of the Related Art
From the viewpoint of principle, an amount of accumulated heat in a thermal type of print head (thermal head) changes (decreases) due to heat dissipation in accordance with elapsed time from previous printing. However, dot rows (dot lines) of a print image, in which dots are arrayed in a tape width direction, have a regular interval therebetween. Therefore, in a conventional tape printing apparatus, heating control (print control) is performed in accordance with a relative moving speed so that the amount of accumulated heat for printing each of the dot lines is within a predetermined range, in other words, so that the amount of heat dissipation is uniform among the dot lines (for example, see FIGS. 9 to 23 and related description in Published Unexamined Japanese Patent Application No. 268360/1999).
However, in the above mentioned principle, no consideration is given to the difference in content of a print image and a printing speed. In concrete, when printing a dot line (print line) which includes at least one dot to be printed (heated), a predetermined amount of accumulated heat can be maintained because of the heating. In case, however, the dot lines (blank lines) including no dots to be printed are consecutive, e.g., when there is a blank between paragraphs or letters in the print image, the print head is cooled down to about ambient temperature. Therefore, even if standard strobe signals are applied for printing the following print lines, a heat quantity required to print each pixel (dot) of the image becomes insufficient. Thus, a size of each dot is reduced and image quality is deteriorated.
The present invention has an advantage of providing a tape printing apparatus as well as a method of controlling the printing by the tape printing apparatus in which applied energy to a print head is adjusted to prevent image deterioration of a print image. The present invention also has an advantage of providing a program and a storage medium.